This photo released by Utah Transit Authority Police Department shows Kay Porter Ricks. Ricks, a Utah train maintenance worker who disappeared amid a manhunt for a father and son accused of a bizarre kidnapping, was found dead along a route that the suspects likely took authorities said Wednesday, May 18, 2016. Police are investigating how Ricks died, and whether the accused kidnapping suspects were involved. (Utah Transit Authority Police Department via AP)
(The Associated Press)

A helicopter circles as law enforcement officials work east of Highway 189 about 16 miles south of Kemmerer, Wyo., Wednesday, May 18, 2016. Law enforcement officials are looking for a possible connection between a missing Utah Transit Authority worker, whose body was discovered late Tuesday evening, and the Centerville, Utah, kidnapping suspects arrested over the weekend. (Ravell Call/The Deseret News via AP) SALT LAKE TRIBUNE OUT; MAGS OUT; MANDATORY CREDIT; TV OUT
(The Associated Press)

AMERICAN FORK, Utah – As the daylight started to fade over the wide-open Wyoming countryside, two officers taking a last look for a missing Utah rail worker spotted a pair of boots.

Then they saw the jeans on the body of 63-year-old Kay Porter Ricks. The Mormon grandfather was found dead along a dirt road Tuesday, five days after he vanished in the middle of his shift in downtown Salt Lake City.

Now, the FBI and investigators in two states are trying to determine if a father and son on the run from police in a bizarre kidnaping case in Utah could have anything to do with his disappearance or death.

"There will be no stone unturned in this investigation," said Utah Transit Authority Police Chief Fred Ross. "We will stay with this as long as it takes."

The death is has been ruled a homicide. Police have not definitively linked Flint Wayne Harrison, 51, and his son Dereck James "DJ" Harrison, 22. But investigators believe the two men were lying low with a friend near where Ricks was working on the day he disappeared. His body was found along the likely route to the campsite where they hid out before their arrest on Saturday.

"There are some coincidences there that would be impossible to ignore as we continue to investigate," Lincoln County Sheriff Shane Johnson told the Deseret News.

Ricks' missing truck could explain how the Harrisons traveled nearly 250 miles from Utah to Wyoming, authorities said.

The Harrisons were arrested over the weekend after a five-day search. The father eventually surrendered and led police to the remote camp near Pinedale, Wyoming.

The two are accused and tying up a woman and her four teenage daughters in a basement on May 10 because they were using drugs and wrongly thought the mother had reported them to authorities. The family managed to break free and escape.

The Harrisons are set to be extradited to Utah to face 16 charges each, including kidnapping and drug possession. Authorities say they are not talking to police.

The Ricks family is mourning their loss rather than speculating on what happened, said family spokesman Richard Massey. Ricks had three grown sons and six grandchildren.

"As you can well imagine, it's difficult explaining to them what has happened to their grandfather," Massey said.

Ricks was a handyman who spent his free time helping neighbors fix their electric lights and ceiling fans. He lived by a regimented daily routine, and would never have left work or gone to Wyoming on his own, Massey said.

Authorities still haven't found Ricks' truck but vowed to keep searching. It was last spotted on surveillance cameras in Wyoming, near where Ricks' body was found south of the town of Kemmerer.